max character in input html code example

Example 1: how to specify amout of letters in inputfield in css

<input maxlength="25" placeholder="name" />

Example 2: input maxlength

<form action="/action_page.php">
  <label for="username">Username:</label>
  <input type="text" id="username" name="username" maxlength="10"><br><br>
  <input type="submit" value="Submit">
</form>